Implant measures medication levels in bloodstream, in real time
By Ben Coxworth
January 23, 2014
Figuring out how much medication a patient should be taking can be a tricky business. Although things like age and weight are used as guidelines, factors such as the individual person's metabolism can have a marked effect on how effective the drugs are. With that in mind, scientists at the University of California, Santa Barbara have developed an implantable device that provides continuous real-time readings on how much medication is currently in a person's bloodstream.
Developed by researchers Tom Soh, Kevin Plaxco and Scott Ferguson, the microfluidic instrument is known as MEDIC (Microfluidic Electrochemical Detector for In vivo Concentrations).
It incorporates a central canal-like chamber, that's lined with gold electrodes. Extending out from those electrodes are DNA strands called aptamers. These can be tuned to recognize specific drug molecules.
When whole blood flows through the chamber, the aptamers detect the presence of the relatively small drug molecules amongst the larger and more numerous blood cells, and respond by wrapping around them. Upon doing so, each strand delivers electrons down into its electrode. This produces a small electrical current, which can be picked up and read by a computer.
In lab tests on rats, the technology has proven to be highly accurate.
It is hoped that once fully developed, MEDIC will allow doctors to "tailor prescriptions to their patients’ specific biology," allowing them to arrive at the optimum dosage sooner. It could conceivably also be used in diagnoses, targeting protein molecules associated with specific diseases.
Down the road, it might additionally be used in conjunction with a drug-dispensing implant, instructing it to release more or less medication as needed.
A paper on the research was recently published in the journal Science Translational Medicine. More information is available in the video below.
Source: UC Santa Barbara